Broomall’s Dam Update: Temporary Partial Breach this fall

As we reported in October 2015, the the PA Department of Environmental Protection (PADEP) will conduct a “temporary partial breach” of Broomall’s Dam this year. This is planned as a temporary dam removal until the proposed new dam is built. By conducting this partial breach, the PADEP is taking action to address the serious safety issue posed by the current Broomall’s Dam, which is a high-hazard dam that was declared unsafe in 1980 by the Army Corps of Engineers.

Timeline

The PADEP originally intended to conduct the partial breach before June 1 this year, but the timeline has been updated. According to Duke Adams of the PADEP Division of Dam Safety, PECO will re-route the gas lines that currently run through the dam by July. Both the gas and water lines that run through the current dam will be permanently re-routed – the proposed new dam would not have utilities running through it.

The PADEP will begin the partial breach in September, and the process should take 6 to 8 weeks. This would mean that the breach should be complete by Thanksgiving. Based on the timing of the dam permit process, the PADEP indicated we are “probably 2 years off from construction” of a new dam – which would take us to spring 2018 for construction of the proposed new dam to begin.

What the partially breached dam will look like

“Preliminary” plan

Officials at the PADEP explained that the top layer of the current dam, including the roadway, will be removed – the resulting structure will be a smaller dam 10 to 12’ lower than the current dam. Upstream of the dam will be a stream in place of the current Broomall’s Lake – the PADEP will allow the stream to find its own channel. In the growing season, the new streambanks should fill quickly with vegetation. During the breach process this fall, there will be a dirt road causeway built upstream for construction access, but it is undetermined if that will remain until construction starts on the new proposed dam.

According to the PADEP, the stream will pass over the lower dam through a flow channel notched out of the top of the dam – there will be a waterfall lower than the current one. Downstream of the dam, there will be some riprap on the park side near the stream, but there will be minimal disturbance to the park. The PADEP indicated that only a few trees closest to the top of the dam will be removed when they take the level down. You can review the pdf of the PADEP’s preliminary partial breach plans, and pdf’s and images are also at the bottom of this article.

Park Access & 3rd Street Access

Officials at the PADEP advised that construction equipment will be staged at the 3rd Street entrance, so the 3rd Street entrance to Glen Providence Park will be closed when they are breaching the current dam, from approximately mid-September through Thanksgiving. The entrance will be open again after the current dam is breached, until construction of the new proposed dam would begin.

As currently planned by the PADEP, there will be barricades on both sides of the dam at 3rd Street – there would be no access for pedestrians or bikers until the proposed new dam is completed. As it is likely 2 years until construction begins, it could mean 3 years without access to cross Broomall’s Run at 3rd Street. Friends of Glen Providence Park has inquired with PADEP and Media Borough Council about constructing a footbridge to cross Broomall’s Run over the lowered dam. We will continue to advocate for a footbridge to allow pedestrian and bike access, keeping the Upper Providence and Media Borough communities connected.

Safety

According to the PADEP, if the partially breached dam fails, sediment would “slowly ooze” – there should not be danger to those in park. In addition, the partially removed dam will have a wider (more stable) base than the current one. The partially breached dam will be classified as C4, meaning there would be no potential loss of life or “public convenience” (road/traffic).

Public notice & public meeting

We asked the PADEP to post signs well in advance of construction advising of the 3rd Street closure and park entrance closure. We also requested a public meeting with the PADEP about the partial dam breach process, similar to the Dam Safety Workshop we hosted in August 2012, so the community can be fully informed and have their questions about the breach process addressed.

Emergency Action Plan signatures

It is our understanding that there are still no signatures on the Emergency Action Plan (EAP) for the proposed new dam, which is required to obtain a dam permit. The PADEP indicated, “There will be no authorization to build [a new dam] until there are signatures.” In July 2015, Media Borough Council passed a resolution that they would not sign the EAP for the proposed dam. As owners and operators of the proposed new dam under the Stipulation Agreement, it is expected that Delaware County and Broomall’s Lake Country Club would sign it.

You can read about and see pictures of the proposed 1.1 acre construction area for the proposed new dam, including the approximately 2/3 acre of Glen Providence Park that would be buried under earthfill, in our 1.1 Acre Photojournal.